Tibial guide

ABSTRACT

A drill guide for determining the site for and drilling a tunnel in a tibia during an anterior cruciate ligament replacement procedure and method for using same are also disclosed. The drill guide utilizes a multiple-point anatomical reference system for determining the most favorable position for the tibial tunnel, based on isometry, freedom from impingement and desired ACL-PCL interaction.

RELATED APPLICATIONS

This is a continuation-in-part of U.S. patent application Ser. No.08/222,082, filed Apr. 4, 1994, now U.S. Pat. No. 5,570,706, which is adivision of U.S. patent application Ser. No. 08/020,901, filed Feb. 23,1993, and issued as U.S. Pat. No. 5,300,077, which is a continuation ofU.S. patent application Ser. No. 07/552,815, filed Jul. 16, 1990, nowabandoned.

TECHNICAL FIELD

The present invention relates to an improved method for reconstructionof a torn anterior cruciate ligament using endoscopic techniques, aswell as new and improved instruments for use with the method. Thepresent invention also relates to an improved drill guide device fordrilling a tibial tunnel in the reconstruction of a torn anteriorcruciate ligament using arthroscopic or endoscopic techniques, as wellas a method for using this device.

BACKGROUND OF THE INVENTION

Most people today are involved in a sport or some other type of physicalactivity. Some of these activities involve a low risk chance of injury,such as walking and swimming, while others involve a high risk chance ofinjury, such as football and skiing.

Damaged ligaments, cartilage and tendons in joints are not an uncommonoccurrence, particularly in some of these high risk activities andsports. One of the joints which requires particular skill and presentsparticular difficulties in repairing is the knee joint.

Numerous improvements in repairing damage to knee joints have been madeover the years, and some of the major advances involve the use ofendoscopic techniques and arthroscopic procedures. Arthroscopic surgeryis particularly useful in excising or repairing damaged knee cartilage.

Endoscopic techniques have also been developed for use in repair andreconstruction of damaged anterior cruciate ligaments (ACL) andposterior cruciate ligaments (PCL). When the ACL in particular hasruptured and is nonrepairable, it is usually replaced in young adultsand the knee reconstructed through use of grafts (biological orsynthetic). Some known methods and techniques which have been used torepair and replace ACL ruptures with grafts are discussed, for example,in Moore U.S. Pat. No. 4,773,417, Goble U.S. Pat. No. 4,772,286 and anarticle by Goble entitled "FLUOROARTHROSCOPIC ALLOGRAFT ANTERIORCRUCIATE RECONSTRUCTION", Techniques Orthop. 1988 2(4):65-73.

The function of the real cruciate ligaments is complicated. The ACL andPCL are three-dimensional structures with broad attachments and acontinuum of fibers. These fibers are of different lengths, havedifferent attachment sites, and are under different tensions. Althoughmany current substitutes for cruciate ligaments have not duplicated thecomplex orientation and operation of normal ACLs, they operate the bestand mimic the normal ACL operation the best when they are placedisometrically. "Isometrically" positioned means that the length of thesubstitute ligament will not change during angular movement of the tibiarelative to the femur; the distance between the affixed ends of theligament remains a constant. Isometric placement maximizes the number offibers that can be taut throughout the range of motion of the knee andallows for early knee motion without generating high ligament strains.

Correct isometric positioning of the ACL graft is an important factorfor a successful operation; isometrically placed grafts provide the moststable knees. Correct isometric placement reproduces correspondingfemoral and tibial anatomic attachment sites and will allow an ACL graftto mimic the normal ACL. Non-isometric graft placement can result inplastic deformation of the ACL substitute, postoperative laxity,abnormal kinematics, or failure of fixation.

The importance of accurate placement of the graft tunnels and ACLsubstitute is shown by the fact that graft placements sometimes onlyseveral millimeters apart produce significantly different strains in thecruciate substitute. A placement of the ACL origin or insertion which istoo anteriorly placed in the knee joint results in a ligament that istaut in flexion, but lax in extension. Posterior placement causes theligament to be taut in extension, but lax in flexion. Only isometrictunnel placement provides stability throughout the range of motion.Therefore, one of the challenges during anterior cruciate ligamentreplacement procedures is the accurate isometric placement of the tibialtunnel.

The preparation of the intercondylar notch is also important as is theproper positioning and placement of the femoral and tibial tunnels.Accurate and sufficient notchplasty prevents impingement of the graftwhich could cause failure or significant complications. Often today theamount and degree of notchplasty is determined during an operation by"feel" or experience. This frequently results in more of the bone in thenotch being removed than is necessary, or in less of the bone beingremoved than is required necessitating later correction in theoperation.

U.S. Pat. No. 5,300,077 to Howell, the inventor herein, disclosesmethods and instruments for ACL reconstruction. Many of the method stepsdisclosed therein for replacement of an ACL are substantially utilizedherein. However, the drill guide and method for using according to thepresent invention represent improvements in that portion of theprocedure surrounding the formation of the tibial tunnel for an ACLgraft.

Additionally, reconstructed knees typically regain more extension, haveless pain and exhibit better stability when anterior cruciate ligamentgrafts are placed without femoral roof impingement. This is true, atleast in part, because impingement of an ACL upon the femoral roofcauses flexion contractures because the graft constrains the knee as amechanical stop. If abrasion progresses to involve all the fibers of thegraft, then the graft can fail, resulting in recurrent instability ofthe knee. To avoid flexion contractures and recurrent instability causedby roof impingement, the tibial tunnel should be positioned posteriorand parallel to the slope of the intercondylar roof with the knee infull extension.

Another related challenge in the ACL replacement procedure is tominimize the amount of bone removed from the femoral intercondylar roofto prevent impingement during extension. Correct placement of the tibialtunnel prevents abrasive wear between the ACL graft and theintercondylar roof while minimizing the extent of roofplasty required toavoid impingement. This results in time and effort savings, andmaximizes the desirable feature of preserving the maximum amount ofnatural bone in the knee. It is another goal of ACL replacementprocedures to create tibial tunnel placement that may allow theimplanted ACL to interact more normally with the PCL.

Standard tibial drill guides place the tibial tunnel in the samerelative position for each patient. The most favorable position is oftendetermined using these devices with reference to a single point on oneof the bone surfaces in the knee joint region. This single referencepoint may be a tibial surface such as the PCL, the ACL stump or anotherpoint of reference. The determination of a favorable tunnel position mayalso involve the use of pins or other ancillary guide devices used inconnection with the main device used for guiding the procedure. The useof such additional devices may cause these procedures to be moretime-consuming and involve a greater amount of effort on the part of thesurgeon. They may also require a greater number of surgical incisionsfor their insertion, and/or may require the use of two hands or morethan one person for their manipulation.

In practice, however, different patients have different anatomiespertinent to formation of the tibial tunnel. The differences in theseanatomies often occur in more than a one-dimensional context. Forexample, the degree of knee extension and the slope of the femoralintercondylar roof vary widely between knees. Therefore, the optimumlocation for the tibial tunnel, with regard to isometry, minimizingimpingement and allowing proper interaction with the PCL may vary amongpatients in more than a one-dimensional context. Because use of a singlereference point places the tibial tunnel at the same relative locationfor each patient, a multiple reference point system that takes severalsurfaces into account can provide superior determination of the optimumtibial tunnel location.

It is an object of the present invention to provide an improved methodusing endoscopic/arthroscopic techniques for reconstruction of ACLs. Itis a further object to provide isometric placements of ACL substitutes,and isometric placements which are objectively accurate andreproducible.

It is also an object of the invention to insure against impingement ofthe ACL substitute/graft in the joint. It is another object of theinvention to provide a system for accurately determining whethernotchplasty needs to be performed in the intercondylar notch to preventimpingement, and then performing the necessary notchplasty.

It is still a further object of the invention to provide an ACLreplacement which is minimally invasive in order to minimize trauma andfacilitate faster patient healing and rehabilitation. It is anotherobject to provide a method of ACL reconstruction which preferably usesbiological grafts from the patient.

Further objects of the invention include development and use of improvedinstruments for ACL operations which help assure accurate and sufficientnotchplasty of the intercondylar notch, and provide an improved methodfor ACL reconstruction.

It is therefore advantageous to develop an instrument for ACLreplacement procedures, and a method for using, that determines customplacement of the tibial graft tunnel, for maximizing isometry,minimizing graft impingement and allowing proper ACL-PCL interaction. Itis also advantageous to develop an instrument that is convenient andquick to use, that minimizes effort required by the surgeon and reducesthe number of ancillary devices required.

SUMMARY OF THE INVENTION

The above and other objects of the invention are met by the inventivemethod of ACL reconstruction and instrumentation which are disclosed andclaimed in this application.

For the improved method, the knee joint is examined to confirm therupture. The patient is anesthetized and the surgical site prepped anddraped. The gracilis and semitendinosus tendons are harvested from thepatient for use as the graft (or another type of ACL substitute isobtained). The graft is prepared for later implantation. Sutures arestitched at the free ends of the tendons for use in grasping andhandling them and the tendons are double-looped forming a compositegraft. The size of the graft is measured in order to select the properdrill/reamer size for the osseous tunnels.

The knee is examined by arthroscopic procedures and any observed minordefects or irregularities are taken care of. The lateral wall of theintercondylar notch is debrided and sculptured (i.e. "wallplasty"). Bothmanual and powered instruments can be used for this purpose. The tornACL stump is removed from the intercondylar notch and the joint iscleaned.

The femoral attachment site for the ACL graft is determined visually andmarked with a small recess by a curette. The femoral lateral cortex isexposed and a rear entry drill guide is utilized to drill a small holethrough the femur to the recess.

A unique transverse drill guide is used to position and place a locatorpin transversely through the femur. The transverse drill guide has anelongated slide bar, a bent wire aimer with a curved tip, a drill sleeveand a drill sleeve positioning member. The aimer has a groove which isadapted to nest with the intercondylar notch in order to accuratelyposition it in place. Once the aimer and attached slide bar arepositioned in place, the positioning member slides on the slide bar andpositions the drill sleeve in the proper position. The transverselocator pin is drilled through the drill sleeve and passes through theintercondylar notch adjacent the curved tip of the aimer.

The transverse locator pin is used to position a unique anterior tibialdrill guide which in turn is used to drill a small hole through theintercondylar roof with the knee in hyperextension. The anterior tibialdrill guide utilizes the same drill sleeve positioning member as thetransverse drill guide and also includes an elongated slide bar and bentwire hook. The curved tip of the bent wire hook is hooked over thefemoral transverse locator pin and the top of the bent wire hook ispositioned against the roof of the intercondylar notch. A small hole isdrilled in the tibia through a drill sleeve situated in the positioningmember on the slide bar.

The small holes in the femur and tibia preferably are then checkedisometrically to determine if they are the proper sites for the osseoustunnels for the ACL graft. A suture passed through the two holes issecured to a button on the lateral femoral cortex and passed through andsecured to a tensiometer on the tibia. The tensiometer is unlocked andreadings are taken during movement of the knee.

If the proposed site is isometric, then the femoral and tibial tunnelsare drilled. Guide pins are positioned in the two tunnels and thetunnels are drilled using cannulated drills or reamers placed over thepins. The inner edges of the tunnels are smoothed and chamfered.

The possible impingement of the roof of the intercondylar notch on thesubstitute ACL graft is then checked. A calibrated sizer is passedthrough the tibial tunnel and any impingement noted. If any impingementis determined, it is marked with a unique gouge instrument and aroofplasty is performed. The sizer is reused and the knee analyzed againuntil all of the impingement has been eliminated.

The substitute ACL graft is then passed through the osseous tunnels andsecured in place. The double-looped end of the graft is affixed to thelateral femoral cortex by a cancellous screw. Once the graft is pulledtightly into position and minimal movement of the graft during rotationof the knee is observed, the graft is affixed to the tibia by bonestaples.

After the graft is fully secured in place and examined, the woundsaround the knee are closed and dressed. A leg brace is installed andappropriate postoperative care is followed.

The present invention also provides a drill guide for determining thesite for and drilling a tunnel in a tibia during an anterior cruciateligament replacement procedure. The drill guide is suitable for use inarthroscopy as well as in open procedures. The drill guide utilizes amultiple-point anatomical reference system for determining the mostfavorable position for the tibial tunnel, based on isometry, freedomfrom impingement and desired ACL-PCL interaction. Preferably, the drillguide is configured in a specialized arrangement to determine isometryat three points of contact. These three points of contact are thetrochlear groove, the femoral intercondylar roof and the tibialeminence. This drill guide enables a surgeon to prepare a customizedtibial tunnel based upon each patient's unique anatomy, includingfemoral roof angle and degree of knee extension. Thus, tibial tunnelplacement can properly vary from patient to patient.

The tibial drill guide includes a drill sleeve for determining the sitefor and drilling a tunnel in a tibia. The drill sleeve includes adrilling axis upon which a drilling procedure can be performed. Thedrill sleeve also includes an aperture suitable for allowing the passageof a drilling device, such as a K-wire or drill bit. The aperturepreferably includes a longitudinal axis disposed upon the drilling axis.The tibial drill guide also includes a guide assembly attached to thedrill sleeve. The guide assembly preferably includes an elongatedpositioning member, a guide arm and an extension located at an end ofthe guide arm. The guide arm and extension are contoured and arranged ina specific configuration. This allows the guide assembly to provide amultiple-point anatomical reference system for aligning the drill sleevein a desired position by contacting three separate knee joint locations.The guide assembly preferably contacts the trochlear groove, the femoralintercondylar groove and the tibial eminence.

The drill guide may also include a collar attached to the guide assemblyfor holding the drill sleeve in a moveable relation. In thisarrangement, the drill guide also includes means for securing the drillsleeve within the collar. This may be provided as a pin threaded intothe elongated positioning member, passing through the collar andabutting against the drill sleeve. In another arrangement, this may beprovided as a pin biased against the drill sleeve and a thumb-actuatedlever by opposing springs.

In the method of the present invention, there is provided a method forreplacement of an anterior cruciate ligament. This method includes amethod for using the tibial drill guide set forth herein. The steps ofthe method include inserting the drill guide into a medial portal of aknee joint and positioning the drill guide in simultaneous contact withthe trochlear groove, the femoral intercondylar notch and the tibialeminence. In the next step of the method of the present invention, thedrill guide is utilized to conduct a drilling procedure, therebycreating a tibial tunnel. This may include using the drill guide tocreate a guide hole, which in turn is used to create a tibial tunnel.

Accordingly, it is an object of the present invention to provide a drillguide for determining the site for and drilling a tunnel in a tibia foranterior cruciate ligament replacement. A related object of the presentinvention is to provide a method for using the tibial guide device.

A further object of the present invention is to provide an apparatus andmethod for anterior cruciate ligament replacement which maximizesisometric placement of an ACL graft tunnel through a tibia.

Another object of the present invention is to provide an apparatus andmethod for anterior cruciate ligament replacement which minimizesimpingement of an ACL graft upon implantation.

A further object of the present invention is to provide an apparatus andmethod for anterior cruciate ligament replacement which allows properreaction of the replacement ACL to the PCL.

An additional object of the present invention is to provide an apparatusand method for anterior cruciate ligament replacement which determinesproper custom placement of the tibial tunnel through the use of multiplereference points upon the surrounding bone anatomy.

Another object of the present invention is to provide an apparatus andmethod for anterior cruciate ligament replacement that minimizesroofplasty in the femoral intercondylar notch.

A further object of the present invention is to provide an apparatus andmethod for anterior cruciate ligament replacement that is convenient andquick to use.

Another object of the present invention is to provide an apparatus andmethod for anterior cruciate ligament replacement which recognizes thatdifferent patients may have different anatomical structure which maycause the determination of the optimum position for an ACL tibial tunnelto vary among patients.

A further object of the present invention is to provide an apparatus andmethod for anterior cruciate ligament replacement that references threelocations upon the knee joint for determining proper location for thetibial tunnel.

Additional objects, advantages and features of the present inventionwill become apparent from the following description and appended claims,taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Various advantages of the present invention will become apparent fromthe following specification and appended claims by reference to thefollowing drawings in which:

FIGS. 1 and 2 are schematic perspective views of the harvesting of thetendons for use as an ACL replacement in accordance with the presentinvention;

FIG. 3 illustrates harvested tendons prepared for use as an ACL graft inaccordance with the present invention;

FIG. 4 is a schematic perspective view of the wallplasty procedural stepfor ACL reconstruction in accordance with the present invention;

FIG. 5 illustrates the marking of the femoral attachment site with acurette;

FIG. 6 illustrates the marking of the location of the lateral femoralincision;

FIG. 7 illustrates the lateral femoral incision procedure;

FIG. 8 shows drilling and positioning of the femoral guide pin with therear entry guide;

FIG. 9 illustrates placement and use of the transverse drill guide toplace the transverse femoral locator guide pin;

FIGS. 10 and 11 illustrate placement and use of the anterior tibialdrill guide to position and place the tibial guide pin;

FIGS. 12 and 13 depict use of a tensiometer in isometrically determiningthe positioning of the osseous tunnels;

FIG. 14 is a cross-sectional view of the tensiometer shown in FIGS. 12and 13;

FIG. 15 illustrates the drilling and formation of the femoral tunnel;

FIG. 16 illustrates the drilling and formation of the tibial tunnel;

FIGS. 17 and 18 illustrate use of the unique sizer member in accordancewith the present invention to determine possible ACL graft impingementin the intercondyle notch;

FIGS. 19 and 20 illustrate use of the unique gouge instrument to markthe location of the roofplasty necessary to eliminate possible ACL graftimpingement;

FIGS. 21 and 22 depict the positioning and securing of a tendon graft inaccordance with the present invention;

FIG. 23 is a perspective view of a drill guide according to the presentinvention prior to positioning for determining the proper site for atibial tunnel;

FIG. 24 is a partial cutaway view of a drill guide according to thepresent invention in position for determining the proper site for atibial tunnel;

FIG. 25 is a side cross-sectional view of the drill guide set forth inFIGS. 23 and 24;

FIG. 26 is an end cross-sectional view of the drill guide set forth inFIG. 25;

FIG. 27 is a side cross-sectional view of another version of drill guideaccording to the present invention;

FIG. 28 is a end cross-sectional view of the drill guide set forth inFIG. 27;

FIG. 29 is a partial cutaway view of a drill guide in a preliminaryinserted position within a knee joint;

FIG. 30 is a partial cutaway view of a drill guide in an insertedposition within a knee joint for guiding the drilling of a tibialtunnel;

FIG. 31 is a partial cutaway view of an impingement rod inserted througha tibial tunnel and partially inserted into an intercondylar roof; and

FIG. 32 is a partial cutaway view of an impingement rod inserted througha tibial tunnel and inserted into an intercondylar roof followingnotchplasty.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

It should be understood that while this invention is described inconnection with particular examples, the scope of the invention need beso limited. Rather, those skilled in the art will appreciate that thefollowing teachings can be used in a much wider variety of applicationsthan the examples specifically mentioned herein.

For a knee reconstruction involving an unrepairable or torn anteriorcruciate ligament (ACL), the procedure begins with a general anesthesiabeing administered to the patient. The patient is positioned supine onthe operating table. A well-padded tourniquet is placed proximal on thethigh of the affected leg, although the tourniquet is not inflated untillater. An arthroscopic leg holder is placed around the tourniquet. Thetable is inclined (e.g. 15° of trendelenburg) and adjusted in height(e.g. waist level) according to the desires of the surgeon. The otherleg is secured to the foot of the table. A Mayo stand is placed over theleg holder and positioned to permit access to the lateral thigh.

The surgical site is prepped and draped with a sterile seal. Standardarthroscopic draping is performed covering the Mayo stand. The lightcord, camera, motorized instruments, and inflow, outflow and suctiontubing are wrapped and secured to the drape on the Mayo stand. Theirrigation stand is set up and positioned.

The joint of the affected leg is examined physically to confirm arupture of the ACL and to determine the amount and degree of movement(joint looseness).

The graft harvesting step in the procedure depends on the type of ACLsubstitute that is to be utilized. In accordance with the presentinvention, preferably the gracilis and semitendinosus tendons areharvested from the patient and used as the ACL substitute. These providea graft which is stronger in the joint (over twice the strength of theoriginal ACL) and has less postoperative morbidity. However, it is alsopossible in accordance with the present invention to use other known ACLsubstitutes, such as patellar tendons, autogenous tendons, frozen andlyophilized tendon allografts, or some of the various known syntheticmaterials. Although the harvesting and preparation techniques may bedifferent or eliminated altogether with other ACL substitutes, theirinstallation and attachment to the femur and tibia are preferably thesame as that described below relative to placement and attachment ofharvested semitendinosus and gracilis tendons.

A tibial incision is used for harvesting the semitendinosus and gracilistendons as well as for use as the site for making the tibial tunnel. Theanterior tibial crest and the posteromedial margin of the tibia areoutlined with a marking pen. The incision overlies a line which bisectsthat outline. A longitudinal incision about 4 cm in length is centeredat a point about three finger widths distal to the anteromedial jointline over the bisecting line.

The incision is made with a No. 15-blade through the skin andsubcutaneous tissue. Electrocautery is used for hemostasis. Subcutaneousfat is elevated off the sartorius expansion from the anteromedial tibialcrest to the posteromedial tibial edge. A rake is used to mediallydisplace the medial edge of the incision and the gracilis tendon ispalpated.

An incision 30 is made in the tibia 32 parallel and inferior to thegracilis tendon by cutting through the sartorius expansion (see FIG. 1).The incision is angled 90° proximally along the medial tibial crest ofthe tibia 32 for approximately 15 mm. With the knee at 90° the gracilistendon 34 is isolated manually and a penrose drain or equivalent deviceis passed around it to maintain tension on it. The tendon is detachedcarefully from the tibia preserving maximal length.

As shown in FIG. 2, the detached end 36 of the tendon 34 is prepared forgrasping by installation of sutures 38 using a No. 1 Ethibond suture anda tendon needle. A number of "whip" stitches are weaved about 4 cm upalong each side of the detached tendon.

The tendon 34 is cut free from attachments along its length bymetzenbaum scissors. The sutures 38 are tugged gently until the tendoncan be seen to move freely.

The gracilis tendon 34 is removed by a tendon stripper 40, such as theclosed end or slotted end tendon strippers marketed by AcufexMicrosurgical, Inc., Norwood, Mass. After the loose end of the tendon ispositioned in or threaded through the stripper instrument 40, the tendonis grasped and held in tension manually by the sutures 38. The stripper40 is slowly advanced up the length of the tendon until the tendon iscompletely separated from the femur 42 and delivered. The strippercircumferentially divides the tendon using its sharp leading edge 44.With this procedure, the length of the harvested tendon is maximized.The length of the tendon should be sufficient so it can be "doublelooped" when used as the ACL replacement graft.

Precisely the same steps and procedures are used to isolate, detach andharvest the semitendinosus tendon. The length of the semitendinoustendon should also be maximized so it can be "double-looped" into astrong graft.

After the two grafts are harvested, they are prepared and sized. (Thepreparation and sizing steps can be performed by a surgical assistantwhile the surgeon continues with the rest of the ACL replacementprocedure). Any remaining muscle fibers are removed from the grafts andwhip stitches are made with No. 1 Ethibond sutures approximately 4 cmfrom the proximal end of each tendon. FIG. 3 shows a double loopedgracilis tendon 34 and a double looped semitendinous tendon 46. Thesutures 38 are attached to the free ends of the tendons with the whipstitches 48. For identification of the tendons and associated sutures,the sutures on each tendon can be tied with a different number of knots(e.g. two knots in the semitendinosus sutures and one knot in thegracilis sutures).

The pair of double looped tendons 34 and 46 are bundled together to forma composite graft 52. An umbilical tape 50 is looped around the midpointof both tendons and is later used to pass the tendons through theosseous tunnels, as explained below.

In order to determine the proper size of the osseous tunnels, thebundled graft 52 (together with the umbilical tape and sutures) arepassed through conventional incremental graft sizing tubes. An averagegraft should fit snugly into an 8 mm sizer which provides a 50 mm²cross-section identical in size to an average ACL. The proper diameterfor reaming is obtained when the graft 52 firmly fits in the sizer; itshould not be loose.

If another type of ACL graft is to be utilized instead of thegracilis/semitendinous tendon graft 52, it should be prepared in asimilar manner. Sutures should be attached to the ends of the graft toaid in grasping, manipulating and securing the graft in place.Incremental sizing tubes are used to size the graft and select theappropriate drills for forming the tunnel. Installation and attachmentof the graft to the femur and tibia are essentially the same as thatwhich will be described below relative to placement and attachment ofgraft 52, although other conventional or standard procedures may beutilized.

The prepared knee is now examined by arthroscopic procedures. Standardanterolateral and anteromedial portals are made for the diagnosticarthroscopy. Proper portal placement is important. Preferably, thelateral portal is made at a location one-third the width of the patellaligament medial to the lateral margin and positioned vertically justinferior to the inferior patella tip. The medial portal is madevertically, just inferior to the inferior patella tip and adjacent tothe medial border of the patella ligament. The two portals should belocated at the same level.

The fat pad is pushed away from the area by distension of the knee anddiagnostic arthroscopy is performed. Any observed meniscal damage,osteophyte and unstable joint surfaces are appropriately treated bystandard arthroscopic techniques and the status of the cruciateligaments is confirmed.

Debriding and sculpting of the lateral side of the intercondylar notch61 is then performed (still without inflation of the tourniquet). Thisis commonly called wallplasty. Preferably a 5.5 mm full-radius synovialresector is used through the medial portal. A conservative trimming ofthe fat pad is accomplished, starting laterally and ending medially.These steps allow better observation of the notch.

The wallplasty is performed using a notchplasty gouge 62, as shown inFIG. 4, to remove 3-5 mm of the lateral condylar wall 64. No bone isremoved from the intercondylar roof 66 at this point.

An up-angled, curved and uterine curette is used through the medialportal to remove the origin (and stump) of the ACL from theintercondylar roof and the wall of the lateral femoral condyle. Theretained synovial and cruciate remnants are cleaned and vacuumed with afull-radius resector. (Care should be taken to protect the PCL 68 andavoid injury to it and its synovium). Preparation is complete when aprobe can be used to palpate the posterior ridge of the intercondylarroof 66 with clear, unobstructed visualization.

The site for placement of the femoral guide pin is then selected. Thisis the first step in determining the location of the osseous tunnels inthe femur and tibia. The placement of these tunnels is important sincethey must enter the joint at the proper anatomic attachment points(where the original ACL was attached).

The reference point for determining the location of the intra articularentrance point of the femoral guide pin is the posterior arch of theintercondylar notch. A nerve-hook probe is manipulated through themedial portal until the angled tip is oriented at the surgeon'sdiscretion relative to the floor and camera projection (preferablyperpendicular). The tip of the probe is positioned to cradle theposterior edge of the intercondylar notch in the over-the-roof position.The tip is then slid forward about 5 mm from the posterior edge androtated either to the 11:00 position (for a right knee) or the 1:00position (for a left knee). This position is then marked by boring asmall recess 70 with an angled cervical curette 72. This is shown inFIG. 5. The pin site selection is confirmed by palpating with the probe.

The arthroscopic instruments and fluid are removed from the joint. Theleg is exsanguinated and the tourniquet is now inflated. Next, thelateral femur is exposed.

The site for the incision on the lateral femur is then determined. Thiscan be determined visually from experience or teaching, or a guideinstrument can be utilized. The front entry guide system by AcufexMicrosurgical, Inc. can be used, for example, as shown in FIG. 6. Theguide 76 is brought into the joint through the lateral portal 82 and thetip 78 is centered in the small recess or hole 70 marked previously withthe curette. The remaining portion of the guide 76 is brought to rest onthe skin 86 overlying the anterolateral femur, just proximal to themetaphyseal flair.

An incision about 4 cm in length is made just proximal to the medialepicondyle and parallel to the long axis of the femur. If the incisionsite is too anterior the guide 76 will not rest on the lateral aspect ofthe skin. If it is too posterior, the guide will hang up on the anteriorskin.

A skin incision 90 is made through the IT-band and the subcutaneous fatis swept off posteriorly. This is shown in FIG. 7. The IT-band isincised and the incision extended distally approximately 10 cm up thethigh. A lateral retractor 92 is placed between the periosteum andmuscle mass. The superior lateral geniculate vessels are identified andcauterized. The periosteum is incised longitudinally and the lateralretractor 94 is replaced deep to it on the anterior femur andstabilized.

As shown in FIG. 8, a rear entry drill guide 80, such as the AcufexMicrosurgical rear entry drill guide system, is then used to drill thehole for the femoral guide pin. The drill guide 80 is positioned andplaced in the joint by a gaff. The tip 84 of the guide is secured in therecess 70. A "bullet" (drill sleeve) 96 is placed in the drill sleevecollar 98 of the drill guide 80. The drill sleeve 96 is hollow having apassageway 100 for placement therethrough of a sharp pointed wire-typedrill 102, such as a K-wire. The front end 104 of the bullet 96 has asharp tri-point and the rear end 106 has a knob for ease of grasping andmanipulation.

Once the tri-point bullet 96 is positioned in the tubular collar 98 withthe tip against the appropriate position on the lateral cortex of thefemur 42, it is locked in place by a long threaded rod 108 positioned inhandle 110 of the, drill guide 80 and operated by turn knob 112. The rod108 is threaded through a threaded opening (not shown) in the collar 98and makes contact with the bullet 96. When the rod is rotated by theknob, it forces the bullet in a fixed engaging relationship with theinner wall of the collar 98 holding the two members firmly lockedtogether.

Once the drill guide 80 and bullet 96 are firmly set in place, the wiredrill (K-wire) 102 is passed through the bullet and drilled into andthrough the femur using a conventional surgical motorized drillinginstrument. Due to the shape of the drill guide 80, the drill 102 placedin the bullet 96 will always hit the tip 84 of the guide wherever it isplaced. Preferably a 2 mm wire drill is used.

After accurate positioning and placement is confirmed arthroscopically,the wire drill is drilled into and out of the passageway several times(preferably 8-10 times) to make a uniform tunnel. The bullet 96 is thenreleased from the collar 98 and removed from the guide 80, leaving theK-wire (or substituted guide pin) in place. The drill guide 80 is alsoremoved.

If desired, a 6 mm cannulated reamer is used to broach the outer femoralcortex to outline the pin tract so that the wire drill or guide pin canbe removed. A 1-PDS suture, loaded on an 18-gauge spinal needle, is thenpassed into the joint through the drilled hole.

It is also possible in accordance with the present invention, to makethe femoral tunnel in another manner. For example, the femoral tunnelcould be made using Acufex's endoscopic system or front entry guidesystem. Other conventional procedures can also be utilized.

Once the positioning of the femoral guide pin has been establishedindicating the prospective position of the femoral tunnel for the ACLgraft, the position for the guide pin for the proposed tibial tunnel isdetermined. A set of unique drill guides of the shape and structureshown in FIGS. 9-11 are used to position and place the tibial guide pin.

First a transverse drill guide 120 is utilized (FIG. 9). The guide 120has an elongated slide bar 122, a bent wire aimer 124 with a curved tip126, a wire drill sleeve 128, and a drill sleeve positioning member 130.The aimer 124 has a notch 132 defining a convex flattened top surface,and is adapted to nest in and mate with the cartilaginous surface 134 ofthe intercondylar notch 61. The tip 126 is curved about 90°.

The positioning member 130 has a base 136 which has a channel in it toallow the member 130 to fit over and slide along the slide bar 122. Athreaded set screw 138 with an enlarged head for manual grasping andtightening is used to hold the member 130 in the desired position on theslide bar. The drill sleeve 128 is received in a collar 140. The collar140 has internal threads which mate with a series of external threads onthe outer surface of the sleeve 128 so that the sleeve can be secured inplace relative to the collar. The sleeve 128 has an enlarged end 142which is used to manually turn and tighten the sleeve in the collar. Thesleeve 128 has a central passageway 129 through it for holding andpositioning a wire-type drill 144.

In use, the transverse tibial drill guide 120 (without the positioningmember 130 thereon) is first put into position. The bent wire aimer 124is brought through the anteromedial portal 150 and aligned so that thenotch 132 is positioned against the cartilaginous surface 134 of theanterior edge of the intercondylar notch. (If the position of the portal150 is not appropriate, then another portal, such as a central patellarportal, can be made and utilized). More particularly, the aimer isplaced against the roof 66 of the intercondylar notch 61 with the kneeat about 30-45° flexion. The notch or "step-off" 132 is placed againstthe anterior aspect of the notch. The guide 120 is held firmly in thisposition approximately perpendicular to the longitudinal axis of thetibia and femur.

The drill sleeve 128 is tightly threaded into the collar 140 of thepositioning member 130 and the positioning member 130 in turn is placedon the slide bar 122. The member 130 is moved along the bar 122 towardthe aimer 124 until the end 152 of the drill sleeve 128 abuts thelateral external surface of the thigh.

A wire drill 144, which preferably is a 0.062 diameter K-wire, ispositioned in the drill sleeve 128 and drilled by any conventionalmotorized drilling mechanism through the lateral femur, (as shown inFIG. 9). The wire drill passes from lateral to medial in the femur 42 tooutline a window to contain the tip of the anterior tibial drill guide160 (as shown in FIGS. 10 and 11) between the intercondylar roof 66, thelateral edge of the PCL 68, and the medial wall of the lateral femoralcondyle 64. The wire drill is advanced just to or into the PCL and notinto the medial femur.

Once the wire drill 144 is installed in place in the femur 42, thetransverse drill guide 120 is removed. The positioning member 130 isloosened and removed from the slide bar 122, and the aimer 124 isremoved from the medial portal. Since the wire drill 144 (or substituteguide pin) is left in position in the femur, it is necessary to rotatethe aimer in order to remove it from the joint. If there is difficultyin removing the hook of the transverse guide from the transverse pin,the pin can be backed away from the PCL until the hook is removed andthen readvanced.

Once in place the wire drill (K-wire) 144 becomes a transverse locatorpin (although it is also possible in accordance with the presentinvention to replace the wire-type drill with a guide pin). The drill orpin is positioned in the joint a few millimeters distal to the roof 66and enters the medial side of the notch approximately where the PCL isattached.

The anterior tibial drill guide 160 is then put into position throughthe anteromedial portal. This is shown in FIGS. 10 and 11. This drillguide 160 has an elongated slide bar 162 and a bent wire hook 164. Thepositioning member 130 which is used on the transverse drill guide 120to position and place the drill 144 acting as the transverse guide pin144 is also used with the anterior tibial drill guide 160.

The base 136 of the positioning member 130 fits over and slides alongthe slide bar 162. The screw 138 is used to hold the member 130 in placeon the bar once it is put in its proper position. A tri-point "bullet"drill sleeve 166 is positioned in the collar 140. A series of threads onthe outer surface of the bullet 166 mate with the threads on the innersurface of the collar 140 and are used to tightly hold the bullet inposition within the sleeve 140. The bullet 166 has a central passageway168 through it for holding and positioning a wire drill (K-wire) 170.

With the knee slowly being extended, the hook 164 is brought into thejoint through the anteromedial portal. The hook is rotated and thecurved tip 172 of the hook 164 is positioned within the "window" overthe drill 144 acting as the transverse guide pin. This sets the positionfor accurately drilling and setting of the tibial guide pin in theproper orientation and position. A curved notch 174 defining a convexlycurved and flattened upper surface of the hook 164 is pushed posteriorlyuntil it is positioned against the anterior aspect of the intercondylarnotch 61 and the hook is tightly held in this position. For thisprocedure, the knee is deflated by removal of irrigation fluid and theknee is placed in maximum hyperextension, usually 5-10°, as shown inFIG. 11.

The anterior tibial drill guide 160 is raised or lifted until the flatupper surface 173 of the hook 164 is substantially perpendicular to thelong axis of the femur 42. The concave lower surface of hook 164 isshaped to receive and nest with the drill 144 acting as the transversepin. Resistance will be felt as the guide attempts to angulate thetransverse pin.

The bullet drill sleeve 166 is positioned in the member 130 and tightlyscrewed into place. The member 130 is then slid over the end 176 of theslide bar 162 until the tri-point end 178 of the bullet abuts againstthe cortex of the tibia 32. With the hook 164 held tightly against theintercondylar roof and the drill guide 160 held perpendicular to thelongitudinal axis of the femur, the bullet drill sleeve 166 is set inthe proper position. The wire drill 170 is placed in the bullet 166 anddrilled through the tibia into the joint by any conventional motorizeddrilling mechanism.

The wire drill (K-wire) 170 is drilled into and out of the drilled holeseveral times to create a uniform tunnel. The positioning member 130 anddrill guide 160 are removed. It is also possible to remove the drill 144acting as the transverse guide pin at this point since it has fulfilledits intended purpose, and substitute a guide pin for the wire drill 170if desired (or remove it entirely).

The location of the original ACL fibers on the tibial joint surface areused as a landmark to check on 30 the placement of the tibial guide pin.The pin should protrude from the tibia into the joint at the originalACL site. When the knee is at maximum passive hyperextension, the pinshould be parallel and 4-5 mm posterior to the intercondylar roof. Ifthe drill 170 is too lateral or medial, then refinement of the guide pinalignment can be accomplished with a 3 or 5 mm hole changer.

The femoral drill hole formed in the manner described earlier and thetibial drill hole formed in the manner described immediately aboveshould be in alignment and substantially parallel to each other. Oncethey are formed, their positions are checked to determine if they areproperly placed isometrically.

In order to assess isometry of the two drill holes for use as thepositioning for the osseous tunnels, a suture is first passed throughthem. This is shown in FIGS. 12 and 13. The suture 180 loaded on thespinal needle in the femoral drill hole 182 is grasped by a grabber inthe joint and pulled through the tibial drill hole 184. A 2 mm suturepasser also is utilized.

A sterile button 186 is tied on the femoral side of the suture and thestitch is pulled through the joint until the button lies flush on thefemoral cortex. A tensiometer (or "isometer") 188 of conventional orknown design is used to test the isometry of the drilled holes. Thesuture 180 is passed through the tensiometer 188 by a suture passer (notshown). The 2 mm tip 190 an the tensiometer is passed up the tibialdrill hole 184 until the slanted surface 192 is firmly seated on thetibial cortex. (See FIG. 13.) The suture 180 is pulled tightly throughthe drill holes 182 and 184 and fastened securely to the end 194 of thetensiometer 188.

The tensiometer 188 is essentially a spring loaded strain gauge. One ofthe preferred types of tensiometers which can be used in accordance withthe present invention is shown and described in the article entitled"ISOMETRIC PLACEMENT OF SUBSTITUTES FOR THE ANTERIOR CRUCIATE LIGAMENT",by Ben Graf, M.D.

As shown in FIG. 14 (together with FIGS. 12 and 13), the tensiometer 188has a slanted front surface 192, a housing 196, a plunger member 198 anda coil spring 200. The plunger 198 fits within the housing 196 in asliding telescopic relationship. The internal end 202 of the plunger isconnected to the coil spring 200 which in turn is connected to theinside of the housing. The end 202 also has a locking post 204 which isadapted to slide along slot 206 or be locked in position in a bayonet or"J-shaped" slot 208. The spring 200 biases the member 198 relative tothe housing.

A scale 210 in millimeters is arranged along the edge of the slot 206 soreadings can be made of the relative position of the post 204.Preferably, the center of the scale at the entrance to the J-shaped slot208 is set at "zero" so that positive and negative strain gauge readingsfrom the zero point can be read in millimeters depending on the movementof the post during operation of the tensiometer 188.

Once the suture 180 is tightly held in position by the button 186 andtensiometer 188, the tensiometer is unlocked (i.e. the post 204 is movedfrom the J-shaped slot 208 to the main slot 206). The knee is manuallytaken through the range of motion from 0-110° and the excursion of thepost 204 on the tensiometer is noted.

If the post movement is less than 1.5 mm then the correct femoral andtibial tunnel sites have been determined. If the readings are not withinthis range, then additional drill holes are made in the manner asdescribed above and the isometric test is repeated.

Once isometry is obtained, the tensiometer 188 and suture 180, togetherwith the button 186, are removed and the guide pins are replaced in thefemoral and tibial drill holes. (This replacement should be checked,especially in patients with soft bones, to be certain that the pins havefollowed the correct pathways into the joint.)

The femoral tunnel 218 is then drilled using a properly sized cannulatedreamer 220 over the guide pin 222. See FIG. 15. As mentioned earlier,the size of the tunnel is determined based on the snug fit of the doublelooped tendon graft 52 in a graft sizer. The reamer 220 should becontrolled and viewed arthroscopically when it enters the joint toprevent inadvertent damage to the intercondylar contents. Preferably,the reamer is drilled in and out of its passageway 8-10 times in orderto make a uniform tunnel. All bone fragments are irrigated from thejoint.

Once the tunnel 218 has been formed, the edges or intra articularmargins of the tunnel in the joint are smoothed and chamfered with acurved rasp. The rasping should be conservative to avoid changing of theposition of the tunnel. The smoothing of the tunnel entrance into thejoint prevents abrasion and potential damage to the graft. A properlysized tunnel plug (not shown) is inserted in the femoral tunneltemporarily and the joint is fully distended.

The same procedure is used to drill the tibial tunnel 230. This is shownin FIG. 16. A properly sized cannulated reamer 232 is used to drill thetunnel over the guide pin 234. All bone chips and fragments are removedin a conventional manner and the tunnel edges are smoothed and chamferedwith a rasp. A temporary hole plug is usually not needed on the tibialside because the ACL remnant at its insertion site seals the hole. Aplug can be used if needed or desired, however.

After the two osseous tunnels 218 and 230 are finished, the possibleimpingement of the intercondylar roof on the substitute ACL graft ischecked. This is accomplished by use of a unique calibrated sizerinstrument 250 which has an elongated rod 252 and a handle member 254.(See FIGS. 17 and 18).

The handle member 254 preferably is knurled for ease of grasping andmanipulation. In accordance with the invention, it is also possible toprovide T-shaped handles or other types of handle members for the sizerinstrument.

The rod 252 is graduated with a series of calibrated markings 256thereon. The markings are in 5 mm increments and are used to determinethe placement and positioning of the sizer relative to the tibial tunnel230.

A sizer member is selected that matches the diameter of the newlydrilled tibial tunnel 230. As shown in FIG. 17, the sizer member 250 isinserted in the tunnel so that the end 258 is positioned flush with theend of the tibia. The sizer is first inserted with the knee flexed atabout 90°. The depth of the sizer 250 into the tibial tunnel is measuredby noting the calibrated markings 256 on the rod 252. The knee, deflatedof irrigation fluid, is then brought into maximum hyperextension. Thisis shown in FIG. 18. The amount of knee extension (angle "A") ismeasured by observing the angle between the femur and tibia from theside.

An attempt is made to push the sizer 250 into the joint. If the sizercannot be pushed 25-35 mm into the joint, then notch impingement exists.The calibrated markings 256 are used to determine whether impingement ispresent.

The effect of untreated notch impingement on ultimate knee extension canbe estimated by slowly flexing the knee while trying to advance thesizer into the notch through the tibial tunnel. The flexion angle atwhich the sizer can be advanced freely into the notch is observed. Thedifference in knee extension from that point to the point of maximumhyperextension indicates the amount of knee extension that would be lostif the impingement was not corrected.

If the sizer member passes all the way into the back of the notch (e.g.30 mm mark) with the knee in hyperextension, then there is noimpingement and it is unnecessary to cut the roof of the intercondylenotch.

As is usually the case, impingement is determined to exist and atailored roofplasty must be performed. Bone is removed from along thesagittal depth of the intercondylar roof. Preferably a gouge instrument270 as shown in FIGS. 19 and 20 is used to mark the location of therequired notchplasty on the roof 66 of the intercondylar notch 61 (i.e."roofplasty"). The gouge has a handle member 272 at one end for ease ofgrasping and manipulation and an elongated shaft or rod 274. The end 276of the shaft is angled and has a sharp pointed tip or cutting edge 278on one side.

In accordance with the invention, the gouge 270 can have any type ofhandle member 272, such as a T-shaped handle or the like. Also, one sideor edge of the handle member is notched or flattened 273 correspondingto the position of the cutting edge on the rod so that the surgeon willbe better able to move and manipulate the tip in the joint.

The diameter of the shaft or rod 274 of the gouge instrument 270 isidentically sized to match the diameter of the tibial tunnel 230. Thisallows for accurate marking of the roof impingement. With the kneemaintained in hyperextension, the gouge 270 is passed through the tibialtunnel until the tip 278 abuts the intercondylar notch surface, as shownin FIG. 20. The location of the impingement is marked by striking thegouge with a mallet. The tip (or cutting edge) of the gouge is rotatedas the gouge is struck forming an outline of the area of impinging bonewhich has to be removed. This outline is typically made in the archformed by the intercondylar roof and lateral wall.

A tailored roofplasty is then performed, removing the outlined boneusing one or more conventional hand-held gouges (not shown). Finalsmoothing and contouring of the roof is accomplished in a conventionalmanner using standard motorized burrs and hand-held rasps.

After the roofplasty is completed, the knee is again hyperextended andthe sizer instrument 250 reinserted into the joint. If the impingementhas been successfully eliminated, the sizer will pass unobstructed intoand out of the joint and into the femoral tunnel 218. If there are stillany obstructions, then additional roofplasty is performed and the sizerinstrument inserted and the joint tested again until all of the possibleimpingement is removed.

In this manner, the possible impingement of the intercondyle roof on thesubstitute ACL graft is 20 identified, outlined, and quickly andaccurately eliminated. Also, the amount of requisite bone removal isconfirmed.

All of the possible impingement is removed before the graft is insertedin place which prevents any possible harm or damage to the graft if anyimpingements are not found until later and further notchplasty has to beperformed with the substitute graft in place. Also, the presentinvention eliminates the need to perform extensive unnecessaryprotective notchplasty that is sometimes performed by "feel" in anattempt to insure against impingement.

The next step is the placement and securing of the graft in the osseoustunnels. This is shown in FIGS. 21 and 22. The graft 52 (FIG. 3) isinserted in the tunnels and joint and permanently affixed in place. Thegraft 52 is passed through the tunnels starting with the tibial tunnel230. An umbilical tape (not shown) is used to draw the graft 52 throughthe tunnels. The umbilical tape is first fed through the femoral tunnel218 and positioned by forceps over the tibial tunnel. A grabber passedup the tibial tunnel 230 pulls the tape through the tibial tunnel whereit is attached to the umbilical tape 50 previously looped around thetendons 34 and 46 or to the tendons themselves.

The double-looped graft 52 is then threaded through the tunnels 218 and230 and pulled through the joint until the end passes out the lateralfemoral cortex. About 2 cm of the double-looped tendon is passed 20 allof the way through the femoral tunnel and the end is held in place by acancellous screw 280.

A 3.2 mm drill hole is made transverse across the femoral metaphysicalflair, from lateral to medial at the junction of the linear aspera andthe previously cauterized geniculates. The depth of the hole is measuredand the hole is tapped for a 6.5 mm cancellous screw 280. The knee isbrought into extension and maximally externally rotated. The cancellousscrew 280 is placed in the hole with a ceramic ligament washer 282 beingprovided under the head of the screw. The end of the double-looped graft52 is looped around the screw and the screw tightened into the lateralcortex.

The sutures 38 which are attached to the other end of the graft 52 andprotrude from the tibial tunnel are pulled tightly to remove anyredundancies in the composite, tendon graft which can occur in snug,well fitting tunnels. The sutures and graft are held firmly in tensionby the surgeon and the junction of the tibial tunnel and graft 52 ispalpated. The knee also is taken through a range of motion to check for"pistoning" (i.e. any excursion or movement of the graft in the tunnel).If there is no pistoning between 90° flexion and hyperextension, thenthe suitability and placement of the ACL graft is assured. For propergraft placement, the graft should slide less than 1 mm out of the tibialtunnel as the knee is brought from 0° to 120° of flexion. This"excursion profile" indicates that the graft will not stretch if it issecured to the tibia with the knee in full extension and externalrotation.

The graft 52 is then affixed to the tibia 32 on the external surface ofthe tibia outside the tibial tunnel 230. Preferably, the end of thegraft 52 is stapled in place with one or more serrated low profile bonestaples 290. If desired, a small trench or channel (not shown) can bemade in the tibia for placement of the end of the tibia. It is alsopossible in accordance with the present invention to secure the graft 52or the sutures to a screw in the tibia similar to the manner in whichthe graft 52 is secured at its other end to the femur. Also, the ends ofthe graft containing the whip stitches can be trimmed from the graftafter it is secured firmly in place.

When the tendons 34 and 46 have been properly harvested for the graft52, sufficient length of tendon should remain extending out of thetibial tunnel to allow placement of two staples 290. When insufficientgraft protrudes, the graft can be secured with one staple and thesutures 38 can be tied to another staple.

After the graft is secured, the knee joint is tested with the Lachmanand drawer tests. The knee should be tighter than the uninjured knee.

The graft is also finally examined arthroscopically to check for anyimpingements. If any are found, they are corrected and removed. Afterthe graft is fully secured and examined in place, the wounds around theknee are closed and dressed, the tourniquet removed, a leg brace isinstalled, and appropriate postoperative care is followed.

Although particular embodiments of the present invention have beenillustrated in the accompanying drawings and described in the foregoingdetailed description, it is to be understood that the present inventionis not to be limited to just the embodiments disclosed, but that theyare capable of numerous rearrangements, modifications and substitutionswithout departing from the scope of the claims hereafter.

Referring now to FIG. 23, there is shown a tibial drill guide deviceaccording to another embodiment of the present invention in operativeassociation with a knee joint, shown generally at 310. The knee joint310 includes a femur 312 and a tibia 314. The femur 312 is shown toinclude at its distal end a femoral intercondylar notch 316 formedbetween medial and lateral condyles, 318 and 320 respectively. The femur312 is also shown to include a trochlear groove 322 located on thearticular cartilage of the distal femur 312 where the patellaarticulates. The tibia 314 is shown to include a tibial eminence 324which is typically a rounded protuberance disposed near the centralsurface at its proximal end. FIG. 23 also shows a tibial drill guide,generally designated by the numeral 330, in an inserted position withinthe knee joint 310 prior to its alignment for drilling a tibial tunnel.

The components of the tibial drill guide 330 will now be described withreference to FIGS. 24, 25 and 26. The tibial drill guide 330 includes adrill sleeve 332 for guiding a drilling procedure. Preferably, the drillsleeve 332 may be of an elongated cylindrical shape, although it will beappreciated that any suitable shape may be used. The drill sleeve 332includes an aperture 334 for allowing the passage of a suitable drillingdevice, such as a K-wire or drill bit. Preferably, the aperture 334 hasan axis 336 disposed along a longitudinal axis which may be its centrallongitudinal axis. To provide means for engaging the external surface ofthe tibia 314, the drill sleeve 332 also includes a tri-point tip 338 atits forwardmost end.

The drill guide 330 also includes a guide assembly 333 that provides amultiple-point anatomical reference system for aligning the drill sleeve332 in a desired position. The guide assembly 333 accomplishes thismultiple-point anatomical reference system by being able to contactseveral different reference points within the knee joint. Preferably,the guide assembly 333 is able to simultaneously contact the trochleargroove 322, the femoral intercondylar roof disposed at the top of thefemoral intercondylar notch 316 and the tibial eminence 324. It will beappreciated, however, that this multiple-point reference system maycontact other knee joint locations or may use other suitable referencepoints for aligning the drill sleeve 332.

In a preferred arrangement, the guide assembly 333 includes apositioning member 340 which may be in the form of an tapered elongatedbar. The positioning member 340 may be of any convenient shape for easein handling. The positioning member 340 may also include any surfaceirregularities or contours that facilitate gripping by hand. Someexamples of these irregularities or contours will be described below inconnection with FIGS. 27 and 28.

The drill guide 330 may preferably be in a configuration where the drillsleeve 332 is adjustable with respect to the guide assembly 333. In apreferred arrangement, the adjustability may be provided by disposingthe drill sleeve 332 within a collar 342 attached to the positioningmember 340 at its lower end. The collar 342 is shown to have an aperture344 that corresponds to the configuration of the drill sleeve 332.Preferably, the aperture 344 is of a substantially cylindricalconfiguration and is sized to allow snug sliding movement of the drillsleeve 332 in a longitudinal direction within the collar 342. The axisof the aperture 344 is centrally located in the collar 342 andsubstantially corresponds to the axis 336 of the drill sleeve 332. Itwill be appreciated, however, that the shapes of the components setforth herein may vary and may be of any suitable shape. Further, it willbe appreciated that the principle of relating one or more dimensionalaspects of the drill sleeve 332 to the guide assembly 333, and inparticular to the collar 342, may be accomplished while altering theshapes and dimensions of the components set forth herein.

To provide means for limiting the longitudinal travel of the drillsleeve 332 within the collar 342, the drill guide 330 further includestwo limiting devices. In this regard, the drill sleeve 332 includes aknob 346 located at its rearwardmost end. The knob 346 is sized to adiameter larger than that of the aperture 334. This provides an abutmentsurface that limits forward travel of the drill sleeve 332 within theaperture 334 when the knob 346 abuts the rear edge of the collar 342.The knob 346 may preferably have a roughened external surface forfacilitating manipulation of the drill sleeve 32 by hand. The drillsleeve 332 also includes an o-ring 348 for limiting rearward travel ofthe drill sleeve 332 within the collar 342. The o-ring 348 is preferablysized slightly larger than the diameter of the drill sleeve 332. In thisconfiguration, the o-ring 348 provides enough resistance to preventrearward travel of the drill sleeve 332 once it abuts against theforward edge of the collar 342. The o-ring 348 is preferably constructedof a compressible material such as an elastomeric rubber. Thus, theo-ring 346 may be deformed sufficiently to allow the drill sleeve 332 tobe pulled through the aperture 344 in a rearward direction along withthe remainder of the drill sleeve 332. This allows the drill sleeve 332to be separated from the remainder of the drill guide 330.

To provide means for securing the drill sleeve 332 in a substantiallystationary position within the collar 342, the drill guide 330 furtherincludes a transverse pin 350 which is located within an aperture 352 ofthe positioning member 340. The transverse pin 350 abuts against thedrill sleeve 332 with force sufficient to prevent the drill sleeve 332from sliding within the collar 342. To provide means for maintainingforce of the transverse pin 350 against the drill sleeve 332, the drillguide 330 further includes a thumb screw 354. The thumb screw 354 islocated at the upper end of the transverse pin 350. The thumb screw 354is threaded into a corresponding threaded bore 356 disposed at the topof the positioning member 332 until the distal tip of the transverse pin350 abuts the drill sleeve 332 with sufficient force to hold the drillsleeve 332 in a stationary position within the collar 342.

To provide means for aligning the drill sleeve 332 in a desired positionfor formation of a tibial tunnel, the guide assembly 333 furtherincludes a guide arm 360. In the arrangement shown in FIGS. 24, 25 and26, the guide arm 360 is attached to the positioning member 340 near itsuppermost end. It will be appreciated, however, that the guide arm 360may be connected to the positioning member 340 at other locations. Theguide arm 360 preferably includes a guide region, generally designatedby the numeral 362, which is located at the forwardmost region of theguide arm 360. As will be more fully discussed below, the guide region362 is configured to provide the multiple-point reference system foraligning the drill guide 330.

The guide region 362 of the guide arm 360 has several specializedsections that work simultaneously to accomplish the guiding procedure.These include a first guide section 364 formed as a first forwardextension of the guide arm 360. The first guide section 364 is operableto contact the trochlear groove 322 of a knee joint. A second guidesection 366 is formed as another portion of the guide arm 360 forward ofthe first guide section 364. The second guide section 366 is operable tocontact the roof of the femoral intercondylar notch 316. The guideregion 362 further includes a third guide section, provided as anextension 368, connected to the second guide section 366 at itsforwardmost end. The extension 368 is an elongated protuberance shapedas a cylindrical section with a cone-shaped tip that includes alongitudinal axis 370. The extension 368 may be integrally formed withthe second guide section 366 of the guide arm 360, or may alternativelybe a separate element affixed to the second guide section 366. The firstguide section 364, the second guide section 366 and the extension 368are sized and oriented in specific relative sizes and configurationswhich will be described in greater detail below. The extension 368includes three surfaces which aid in proper positioning and function ofthe drill guide 330. These include a tip 372 located at its distal end,a heel 374 located at the proximal end of the extension 368 and a stop376 which is a flattened region located on the surface of the extension368 facing the drill sleeve 332 in the region of the axis 336. It willbe appreciated that the extension 368 may be integrally formed with thesecond guide section 366 of the guide arm 360 (as discussed below inconnection with FIG. 27). The extension 368 may also be a separateelement affixed to the second guide section 366, as shown in FIG. 25.Thus, the heel 374 may be either the end portion of the guide arm 360 orthe upper portion of the extension 368. However, for purposes ofsimplicity and explanation, this component will be referred to as aportion of the extension 368.

As shown FIG. 24, the tibial drill guide 330 performs its guidingfunction through the contacting of three surfaces of a knee joint. Whenplaced in a fully inserted position with the knee in full extension orin slight hyperextension as shown in FIG. 24, the tibial drill guide 330preferably guides the drilling procedure by being simultaneously lockedin contact with three separate points of the anatomy of the knee joint310 (e.g., the trochlear groove 322, the roof of the femoralintercondylar notch 16 and the tibial eminence 324). In this regard, thefirst guide section 364 contacts the trochlear groove 322, while the tip372 of the extension 368 contacts the tibial eminence 324. At the sametime, the heel 374 of the extension 368 contacts the roof of the femoralintercondylar notch 316.

It has been found that constructing the drill guide 330 to includeseveral parameters enhances the ability of the drill guide 330 toproperly locate the tibial tunnel. A first parameter is the angle θbetween the axis 336 and the longitudinal axis 370 of the extension 368.Preferably the angle θ is approximately 100°±5°. A second parameter isthe angle Φ between the first guide section 364 of the guide arm 360 andthe axis 336. This angle is preferably approximately 70°±5°. Anotherparameter is the length of the extension 368, as measured in a directionperpendicular to the axis 336. This parameter, represented by the lettera, is preferably 20 mm±5 mm. Another parameter is the distance b,measured form the uppermost point of the heel 372 to the axis 336. Thisdistance is preferably 5 mm±3 mm.

It will be appreciated that since the most favorable position for atibial tunnel will depend upon the relative sizes and configurations ofthe femur and tibia, any or all the measurements set forth herein may bevaried as necessary to determine the proper tibial tunnel location. Forexample, the dimensions of several or all of the components may besmaller or larger for use with smaller or larger patients. Thus, theproper size of drill guide 330 for a particular patient may bedetermined by reference to x-ray measurements of the patient's kneejoint. Preferably, the drill guide 330 is constructed of 17-4 stainlesssteel, although it will be appreciated that any suitable material may beused.

Referring now to FIGS. 27 and 28, there is shown an alternate embodimentof the drill guide of the present invention which is generallydesignated by the numeral 380. The drill guide 380 includes apositioning member 382 that is contoured on its external surfaces forproviding a hand grip. The positioning member 382 has an aperture 384disposed upon a longitudinal axis thereon. A collar 386 is attached tothe positioning member 382 at its lower end in substantially similarconfiguration to the previous embodiment of the drill guide 380. Thecollar 386 includes a cylindrically shaped aperture 388 whose centrallongitudinal axis defines a drilling axis 390. The aperture 388 isoperable to allow the passage therethrough of a drill sleeve such asthat shown at 332 in connection with FIGS. 24, 25 and 26. It will beappreciated, however, that the collar 386 may be a discontinuous pieceof material as shown in FIG. 28.

To provide means for securing a drill sleeve 332 in a substantiallystationary position within the collar 386, the drill guide 380 includesa lever 392 which is located near the top of the positioning member 382.The lever 392 pivots upon a pivot point 394 that is connected to the topof the positioning member 382. The lever 392 interacts with a transversepin 396 disposed within the aperture 384 of the positioning member 382.

To provide an upward force for releasing the transverse pin from contactagainst a drill sleeve 332 disposed within the collar 386, biasing meansis provided in the form of a coil spring 398. The coil spring 398 ispreferably disposed within a recess 400 at the top portion of theaperture 384. To provide a downward force for causing the transverse pinto contact a drill sleeve 332 disposed within the collar 386, anotherbiasing means is provided in the form of a leaf spring 402. The leafspring 402 is attached to the upper portion of the positioning member382 by a fastener 404 to provide a downward force upon the lever 392.The leaf spring 402 thus maintains a downward force on the transversepin 396 greater than the upward force exerted by the coil spring 398.This allows the transverse pin 396 to contact a drill sleeve 332disposed within the collar 386 with sufficient force to maintain thedrill sleeve 332 in a substantially stationary position. A head 406 ispreferably integrated with the transverse pin 396 and is positionedbetween the spring 398 and the lever 392 to provide an abutment surfacefor the lever 392 and a bearing surface for the spring 398.

The drill guide 380 also includes a guide arm 410 which is similar tothe guide arm 360 set forth in the prior embodiment of the presentinvention. However, the guide arm 410 is contoured on its externalsurfaces for facilitating manipulation by hand. The contour of the guidearm 410 may be integral formations with the contour of the positioningmember 382 as is shown in FIGS. 27 and 28. The guide arm 410 includes aguide region 412 having a first guide section 414 and second guidesection 416 in substantially similar manner as before. These areoperable to simultaneously contact the trochlear groove and the roof ofthe femoral intercondylar notch in a manner similar to that discussedabove. The drill guide 380 also includes a third guide section in theform of an extension 418 having a longitudinal axis 420, a tip 422, aheel 424 and a stop 426, which are similar to that described above. Themagnitude of the parameters a, b, θ and Φ are all substantially the samefor this embodiment of drill guide 380 as with the prior embodimentdiscussed above.

The method of using the drill guide of the present invention will now bedescribed with reference to FIGS. 29-32. It will be appreciated that thedrill guide of the present invention is used within an anterior cruciateligament replacement procedure and that many steps of which are wellknown to those skilled in the art. Accordingly, the present discussionwill focus on the steps unique to use of the drill guide of the presentinvention, along with other steps where desirable to maintain context orto provide better explanation. In addition, while it will be appreciatedthat the placement steps of the method described herein are suitable foruse with various embodiments of the drill guide, reference will be madeonly to the embodiment of the drill guide designated by the numeral 330for ease of explanation.

The first step of the method of the present invention involves medialportal placement. In this step, the surgeon palpates the medial andlateral edge of the patellar tendon and marks these with a pen. A medialportal is then created adjacent the medial edge of the patellar tendon.A medial portal is preferred over a traditional anteromedial portal sothat the drill guide 330 will center properly within the intercondylarnotch.

In the next step of the present invention, the drill guide 330 isinserted into the medial portal with the knee in flexion as shown inFIG. 29. The drill guide 330 is advanced so that the tip 372 of theextension 368 passes between the posterior cruciate ligament and thelateral femoral condyle. The drill guide 330 is further advanced untilthe heel 374 is inside the femoral intercondylar notch 316 facing theintercondylar roof.

Once the drill guide 330 is in the above position, the drill guide 330is seated by initially extending the knee slowly while the surgeon viewsthe relationship between the guide arm 360 and the trochlear groove 322.The movement of the knee is continued toward full extension, whilemanipulating the drill guide 330 to place it in the position indicatedbelow. This may preferably be accomplished by placing the heel on araised Mayo stand. The drill guide 330 is partially seated when the kneeis fully extended while the first guide section 364 of the guide arm 360is flush against the trochlear groove 322 with the tip 372 and heel 374disposed within the femoral intercondylar notch 316.

According to the next step of the present invention, the drill guide 330is positioned to be fully seated. This involves gently pulling the guidearm 360 in an upward direction as shown in FIG. 30 with the long andring fingers while simultaneously hyperextending the knee passively bypushing the patella in a downward direction with the hypothenar surfaceof the same hand. This is continued until a resistance is felt whichindicates that the drill guide 330 is aligned and will create a tibialtunnel that will be posterior and parallel to the slope of theintercondylar roof with the knee in full extension. In thisconfiguration, the first guide section 366 contacts the trochlear groove322 while the heel 374 contacts the roof of the femoral intercondylarnotch 316 and the tip 372 contacts the tibial eminence 324 as shown inFIG. 24.

The drill sleeve 332 is then advanced forward within the collar 342 sothat the tri-point tip 338 contacts the tibia 314. The thumb screw 354is then tightened to secure the drill sleeve 332 in a substantiallystationary position. In the embodiment of the drill guide represented by380 in FIGS. 27 and 28, the lever 392 is depressed which releases thetransverse pin 396 from contact with the drill sleeve. The drill sleevecan then be moved forward until it abuts the tibia, after which thelever 392 is released which secures the drill sleeve in a substantiallystationary position.

In the next step of the present invention, the tibial tunnel is createdusing the drill guide 330. This is preferably accomplished by firstutilizing the drill guide 330 to create a guide hole and subsequentlyusing the guide hole to create a tibial tunnel. With the drill guide 330fully seated, a drilling device, such as a 2.4 mm drill tip K-wire shownat 430 in FIG. 30, is placed through the aperture 334 of the drillsleeve 330. The K-wire 430, or other drilling device, is powered by asuitable device, such as hand drill 432, and is advanced into the tibia314 until the K-wire 430 penetrates the subchondral bone of the tibia314. The drill guide 330 is then disassembled and the K-wire 430 istapped into the knee joint 1-2 cm. An arthroscope is then preferablyinserted through a lateral portal to assess the placement of thedrilling device. Since the position of the K-wire 430 has beencustomized to the patient's particular anatomy with regard to roof angleand degree of knee extension, this position will vary from one patientto another. With the knee in full extension, there should be only 2-3 mmof space between the roof of the femoral intercondylar notch 316 and theK-wire 430. Medial-laterally, the K-wire 430 should touch or be justlateral to the lateral edge of the posterior cruciate ligament at 90° offlexion, and centered within the lateral half of the femoralintercondylar notch 316 near terminal extension. Once the properplacement of the K-wire is verified, the K-wire 430 is then used tocreate a tibial tunnel. This is preferably accomplished by placing anappropriate sized cannulated reamer over the K-wire 430 and drilling thetibial tunnel by methods well known to those skilled in the art.

Once the tibial tunnel is formed according to the steps above,impingement of an ACL graft within the femoral intercondylar notch isassessed. The knee is placed in maximum extension and an impingement rodor sizer member of the type shown in FIG. 31 at 434, having the samediameter as the tibial tunnel, is inserted through the tibial tunnelshown at 440 and into the femoral intercondylar notch 316. If passage ofthe impingement rod 434 is obstructed, roof impingement exists andremoval of bone within the femoral intercondylar notch 316 is necessary.A roofplasty and/or wallplasty is then performed according to methodswell-known to those skilled in the art using suitable tools, such as aroof gouge and angled wall osteotome. Bone is removed from within thefemoral intercondylar notch 316 until it can be estimated through theuse of the impingement rod 434 that impingement will be eliminated. Thisis confirmed once the impingement rod 434 can be freely placed throughthe tibial tunnel 440 and into the femoral intercondylar notch 316 withthe knee in full extension, as shown in FIG. 32. The remainder of theACL replacement surgery is then performed using methods well-known tothose skilled in the art.

While the above detailed description describes the preferred embodimentof the present invention, it should be understood that the presentinvention is susceptible to modification, variation and alterationwithout deviating from the scope and fair meaning of the subjoinedclaims.

What is claimed is:
 1. An arthroscopic drill guide for use in drilling atunnel in a knee joint having a femur with an intercondylar roof and atrochlear groove, and a tibia having a tibial eminence, said drill guidecomprising:a drill sleeve defining an aperture extending along adrilling axis, said aperture operable to guide a drilling procedure; apositioning member extending from said drill sleeve, said positioningmember operable to be gripped by a user; and a guide arm having aproximal end and a distal end, said proximal end in mechanicalcommunication with said positioning member and said distal end includinga guide region, said guide region having a guide section operable tocontact the trochlear groove and an extension having a distal tipoperable to contact the tibial eminence and a bulbous heel positionedopposite said distal tip operable to contact the intercondylar roof ofthe femur.
 2. The arthroscopic drill guide as defined in claim 1 whereinsaid extension further includes a flattened stop region between saiddistal tip and said bulbous heel, said flattened stop region operable tostop a drill passing through said aperture.
 3. The arthroscopic drillguide as defined in claim 2 wherein said stop region is formed by anotch in said extension having a flattened region.
 4. The arthroscopicdrill guide as defined in claim 1 wherein said guide section extendsalong a substantially straight axis.
 5. The arthroscopic drill guide asdefined in claim 4 wherein an angle between said axis of said guidesection and said drilling axis is about seventy degrees (70°).
 6. Thearthroscopic drill guide as defined in claim 1 wherein said positioningmember includes a collar operable to adjustably receive said drillsleeve, said positioning member having a securing mechanism operable tosubstantially secure said drill sleeve within said collar in asubstantially stationary manner, said securing mechanism including atransverse pin extending substantially through said positioning member.7. The arthroscopic drill guide as defined in claim 6 wherein saidsecuring mechanism further includes a biasing member in communicationwith said transverse pin and operable to maintain said drill sleeve in asubstantially stationary position within said collar.
 8. Thearthroscopic drill guide as defined in claim 1 wherein said extensionextends along a substantially straight axis, said substantially straightaxis being positioned relative to said drilling axis at an angle ofabout one hundred degrees (100°).
 9. The arthroscopic drill guide asdefined in claim 1 wherein said extension member has a length asmeasured substantially perpendicular to the drilling axis of abouttwenty millimeters (20 mm) with said bulbous heel being positioned aboutfive millimeters (5 mm) above said drilling axis.
 10. An arthroscopicdrill guide for use in drilling a tunnel in a knee joint having a femurwith an intercondylar roof and a trochlear groove, and a tibia having atibial eminence, said drill guide comprising:a drill sleeve defining anaperture extending along a drilling axis, said aperture operable toguide a drilling procedure; a positioning member extending from saiddrill sleeve, said positioning member operable to be gripped by a user;and a guide arm having a proximal end and a distal end, said proximalend in mechanical communication with said positioning member and saiddistal end including a guide region, said guide region having anextension extending along an extension axis that substantially extendstransversely across said drilling axis, said extension having a distaltip positioned adjacent to said drilling axis, a spherical heelpositioned opposite said distal tip, and a stop region positioned atsaid drilling axis.
 11. The arthroscopic drill guide as defined in claim10 wherein said distal tip is conically shaped and said heel is bulbousshaped.
 12. The arthroscopic drill guide as defined in claim 10 whereinsaid stop region is a substantially flattened region positioned toengagingly receive a drill member.
 13. The arthroscopic drill guide asdefined in claim 10 wherein said extension axis is positioned relativeto said drilling axis at an angle of about one hundred degrees (100°).14. The arthroscopic drill guide as defined in claim 10 wherein adistance from said distal tip to said drilling axis is about twentymillimeters (20 mm) and a distance from said heel to said drilling axisis about five millimeters (5 mm).
 15. An arthroscopic drill guide foruse in drilling a tunnel in a knee joint having a femur with anintercondylar roof and a trochlear groove, and a tibia having a tibialeminence, said drill guide comprising:a drill sleeve defining anaperture extending along a drilling axis, said aperture operable toguide a drilling procedure; a positioning member extending from saiddrill sleeve, said positioning member operable to be gripped by a user;and a guide arm adjustably secured relative to said positioning member,said guide arm having a proximal end and a distal end, said proximal endbeing in adjustable communication with said positioning member and saiddistal end being substantially positioned at said drilling axissubstantially throughout adjustment of said guide arm relative to saidpositioning member, said distal end including a distal tip operable toreference a first landmark within the knee joint and a guide surfaceopposite said distal tip operable to reference a second landmark withinthe knee joint, said guide arm having a substantially convex surfaceproximal of said distal tip and a substantially concave surface adjacentto said substantially convex surface, whereby said guide arm is operableto locate said drill sleeve in a desired position for drilling thetunnel by referencing the first and second landmarks within the kneejoint.
 16. The arthroscopic drill guide as defined in claim 15 whereinsaid first landmark within the knee joint is a transverse pin insertedwithin the knee joint and said second landmark is the intercondylarroof.
 17. The arthroscopic drill guide as defined in claim 15 whereinsaid substantially convex surface is defined by convexly curved andflattened surfaces which are operable to contact the intercondylar roofof the femur.
 18. The arthroscopic drill guide as defined in claim 15further comprising an elongated sliding bar coupled to said guide armand slidably coupled to said positioning member, whereby said guide armis adjustably secured relative to said positioning member.
 19. Thearthroscopic drill guide as defined in claim 15 wherein said guide armfurther includes a second substantially convex surface relative to saidsubstantially convex surface.
 20. An arthroscopic drill guide for use indrilling a tunnel in a knee joint having a femur with an intercondylarroof and a trochlear groove, and a tibia having a tibial eminence, saiddrill guide comprising:a drill sleeve defining an aperture extendingalong a drilling axis, said aperture operable to guide a drillingprocedure; a positioning member extending from said drill sleeve, saidpositioning member operable to be gripped by a user; and a guide armhaving a proximal end and a distal end, said proximal end in mechanicalcommunication with said positioning member and said distal end having adistal tip operable to reference a first landmark within the knee joint,said guide arm having a first substantially straight portion at saidproximal end and a second substantially straight portion at said distalend, said guide arm further having a substantially convex portion and asubstantially concave portion adjacent to said substantially convexportion positioned between said first substantially straight portion andsaid second substantially straight portion, whereby said guide arm isoperable to locate said drill sleeve in a desired position for drillingthe tunnel by referencing the first landmark within the knee joint. 21.The arthroscopic drill guide as defined in claim 20 further comprising asecond substantially convex portion relative to said substantiallyconvex portion adjacent said distal tip having a flattened upper surfacewhich is operable to contact the intercondylar roof of the femur. 22.The arthroscopic drill guide as defined in claim 20 wherein said firstlandmark within the knee joint is a transverse pin inserted within theknee joint.